Prewash stain remover compositions for the laundry have been in use for many years. These compositions are available in liquid, spray and semi-solid stick form. The consumer applies the stain remover to the soiled portions of the garments before washing with a laundry detergent.
While pretreaters have been shown to improve cleaning of soiled areas before the use of the laundry detergent, such stain removers have not proven equally effective in all forms and for all types of stains and fabrics.
Solvent based compositions were formulated to remove difficult grease or oil stains from fabric surfaces from lipophilic fabric surfaces such as polyester and blends of polyester blends. Aqueous based formulations were developed to remove water based stains including those stains which are sensitive to oxidation and enzymes (see U.S. Pat. No. 4,842,762).
Formulators have recently moved away from solvent based formulations to provide more environmentally, friendly products (see U.S. Pat. No. 4,595,527 S. C. Johnson). Cleaning can be compromised in solvent free systems, thus aqueous based formulations based on nonionic surfactants were developed. The cleaning performance of such pretreaters was improved by incorporating builders or chelants in the formula (see U.S. Pat. No. 4,595,527). However, many of these chelants caused the formulations to separate and enzymes or actives were not specifically directed to the soiled areas.
U.S. Pat. No. 5,186,856 (BASF) describes a solvent free pretreater based on a chelating agent which does not exhibit separation.
However, there still exists a need in the art for a stable aqueous pretreater based on non-ionic surfactants which can be directed to penetrate both oil and water based stains for improved cleaning performance.
It is therefore an object of the present invention to provide an aqueous laundry stain pretreater composition which provides outstanding cleaning performance on both oil and water based stains on a variety of fabrics.
Another object of the present invention is to provide a pretreater composition which is based on nonionic surfactants and which incorporates a silicone wetting agent to penetrate stained areas of fabrics for improved cleaning performance.
Another object of the invention is to provide an aqueous nonionic based pretreater composition which is shelf stable and which is free of chelating agents yet does not compromise cleaning performance.